Oilfield operators demand access to a great quantity of information regarding the conditions encountered downhole. Such information typically includes characteristics of the earth formations traversed by the borehole and data relating to the size and configuration of the borehole itself. The collection of information relating to conditions downhole, which commonly is referred to as “logging,” can be performed by several methods including “logging while drilling” (LWD) and wireline logging.
Among the available wireline and LWD tools are a variety of acoustic logging tools including, in particular, ultrasonic “caliper” tools. Such tools employ acoustic signals to perform measurements, for example, measuring a distance to the borehole wall. With an appropriate set of such distance measurements, the borehole size and shape can be estimated, as well as the relative position of the tool within the borehole.
Acoustic transducers face many performance challenges including the “ring down” phenomena due to the transducer's mechanical motion failing to instantly cease when a driver signal is removed. Rather, there is some residual motion and vibration which must be suppressed or otherwise accounted for. This phenomena may be reduced by use of improved transducers, however, such may prove costly when compared to off-the-shelf transducers currently available and used.
It should be understood, however, that the specific embodiments given in the drawings and detailed description thereto do not limit the disclosure. On the contrary, they provide the foundation for one of ordinary skill to discern the alternative forms, equivalents, and modifications that are encompassed together with one or more of the given embodiments in the scope of the appended claims.